Magnetic surgical/oral retractor

ABSTRACT

A magnetic oral retractor assembly for distending the cheek of a patient undergoing an oral dental/surgical procedure comprises a gripper element mounted to a support structure external of the patient&#39;s oral cavity and an intraoral retractor device for contacting the inner surface of the patient&#39;s cheek. The gripper element and the retractor device each include a magnetic member, at least one magnetic member being a magnet and the other being either another magnet or a non-magnetized magnetically permeable member. The magnetic members are positioned on the gripper element and the retractor device for magnetically coupling the gripper element to the retractor device through the patient&#39;s cheek. The invention has application in surgical procedures to secure patient tissue magnetically in place during surgical procedures or to distend an opening in a patient&#39;s body wall during an open surgical procedure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to devices and apparatus for providingaccess to areas undergoing a surgical/dental procedure, and moreparticularly, to tissue retractors incorporating magnets.

2. Description of Related Art

There are myriad surgical/dental procedures that require access to hardto reach areas of a patient. One part of the body that has provedparticularly challenging in terms of access to target areas undergoingsuch procedures is the buccal surfaces of the gums and/or teeth in apatient's oral cavity. Increases in both the efficiency and efficacy ofthese procedures are obtained by providing the dentist or surgeonunfettered access to the area being treated. In addition, surgicalprocedures on other areas of the body frequently require retraction oftissues not involved in the procedure, or securing tissues in placeduring the procedure, to expose the area.

The most common approach to providing sufficient space for a dental orsurgical procedure is simply to manipulate the tissues not involved andretract them out of the way. For example, a dentist or oral surgeon mayengage the edges of a patient's mouth using a manual retractor devicethat fits over the patient's lips and pulls them back as far as theywill stretch. Typical such devices are shown in U.S. Pat. No. 4,971,557,U.S. Pat. No. 5,115,799, U.S. Pat. No. 5,730,597, U.S. Pat. No.6,080,105, and U.S. Pat. No. 6,102,701. Such a retractor device mayinclude a contoured surface that fits over the patient's lips and ahandle portion for the surgeon, or more commonly, an assistant, to pullmanually to retract the patient's lips from the target area.Alternatively, the dentist may use a dental mirror to provide retractionof the buccal tissue while performing the procedure with thecontralateral hand. In this manner, the patient's mouth is forciblyexpanded and the dentist/surgeon is afforded access to the target area.

This is an imperfect approach because it requires either that the dentalpractitioner hold the retractor with one hand while performing theprocedure with the other, or that an assistant be employed to hold theretractor. The presence of an assistant increases the cost of theprocedure to the patient. And even if an assistant is required for otheraspects of the procedure, a manual retractor perforce still occupies oneof the assistant's hands, thus limiting his or her ability to performother tasks during the procedure. And using a dental mirror can limitthe dentist's visual field because the mirror is first placed as aretractor, and only secondarily as a visual tool.

While these retraction techniques may be acceptable in somecircumstances, access to the target area is still limited because thepatient's lips can only be distended so far. Moreover, retracting justthe lips has a limited effect on moving the buccal surfaces of thecheeks away from the teeth and gums, particularly when the target areais deeper within the patient's oral cavity, such as proximate to themolars. Yet another drawback to using retractors that pull on thepatient's lips is that the retractor itself tends to interfere with theprocedure because it occupies part of the opening through which thesurgeon/dentist accesses the target area. It is also known to usevarious forms of gauze packing between a patient's buccal surfaces andteeth to provide a degree of access. However, this can severely limitthe amount of working space immediately adjacent the target area.

Retraction of tissues in non-dental surgical procedures typically relieson manipulating the uninvolved tissues and moving them out of the way,or packing the tissues and/or organs off (that is, away from the targetarea) with laparotomy pads, surgical towels, or other similar compliantimplements that conform to the shape of the tissues/organs being held inplace. Unlike retraction in dental procedures, a surgeon can oftenenlarge an incision to provide greater access to the target area. Buteven then, additional manipulation of internal tissues and/or organs isoften required to maintain adequate exposure of the target area afteraccess is achieved. For example, in open abdominal surgery, an incisionof adequate size can usually be made to provide access, butintra-abdominal tissues and organs (such as the spleen, intestines,etc.) may need to be manipulated to expose the surgical site. This isoften accomplished using devices such as Balfour retractors orBookwalter retractors to hold the wound edges open. These devicesincorporate retractor blades of various shapes, and are often used incombination with laparotomy sponges, surgical towels, or other soft,malleable instruments. These devices can decrease the amount of spaceimmediate to the surgical wound, and thus decrease the space for thesurgeon to work, but they are necessary to secure the retractorimplements and maintain the tissues/organs in a retracted position. Insome cases, a sufficient number of laparotomy sponges may be used tomaintain the desired position of the tissues without requiring a bladeretractor. But the position of the tissues will often change if held inplace only by laparotomy sponges, and adjustments will have to be madeduring the surgery. Moreover, the use of multiple laparotomy sponges isinherently dangerous, since it increases the risk that one or moresponges will remain in the patient after the surgery is completed.

Accordingly, there has been a long-felt need for an improved manner ofexposing areas that are targeted for surgical/dental procedures tofacilitate the procedures and increase their efficiency and efficacy.

SUMMARY OF THE INVENTION

It is an object of the invention to overcome the disadvantages of theprior art by providing an improved apparatus and method for retractingbody tissues during surgical/dental procedures.

In accordance with one aspect of the invention, a magnetic oralretractor assembly for distending the cheek of a patient undergoing anoral dental/surgical procedure comprises a gripper element mounted to asupport structure external of the patient's oral cavity and an intraoralretractor device for contacting the inner surface of the patient'scheek, wherein the gripper element and the retractor device each includea magnetic member, at least one of the magnetic members comprising afirst magnet, and the other of the magnetic members comprising a secondmagnet or a non-magnetized magnetically permeable member, the magneticmembers being positioned on the gripper element and the retractor devicefor magnetically coupling the gripper element to the retractor devicethrough the patient's cheek.

In a more specific embodiment, the magnetic oral retractor assemblyfurther comprises at least four lip holders, each including a lip clampfor grasping the patient's lip, each clamp being mounted at a distal endof a separate adjustable arm with a proximal end removably attachable tothe support structure, and at least two gripper elements, each of whichis mounted on a distal end of a separate mounting arm, the mounting armshaving their proximal ends adapted to be removably attached to thesupport structure for use with opposite sides of the patient's oralcavity, wherein pairs of the lip holders are disposed for use with anassociated gripper element to hold the upper and lower lips on oppositesides of the patient's oral cavity.

In another aspect of the invention, a magnetic surgical retractorassembly for securing tissue of a patient undergoing a medical procedurecomprises a gripper element and a retractor device for engaging aportion of the tissue, wherein the gripper element and the retractordevice each include a magnetic member, at least one of the magneticmembers comprising a first magnet, and the other of the magnetic memberscomprising a second magnet or a non-magnetized magnetically permeablemember, the magnetic members being positioned on the gripper element andthe retractor device for magnetically coupling the gripper element tothe retractor device to enable the gripper element to exert a force onthe retractor device to manipulate the tissue.

This aspect of the invention can be embodied in numerous constructions.For example, the retractor device can be adapted for placement within alumen of a hollow organ or a space within a tissue so that the gripperelement interacts magnetically with the retractor device through a wallof the organ or tissue interface. The gripper element can includestructure for extending through a body wall of the patient for securingthe organ or tissue within the body cavity at a location spaced from thebody wall. This aspect of the invention is further applicable tostructure in which the gripper element and the retractor device areadapted to interact magnetically with each other through a body wall ofthe patient. In addition, the retractor device can include a compliantsurgical implement such as a laparotomy sponge or surgical towel thathas been modified to be either a magnet or magnetically permeable.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects of the invention will be better understood from the detaileddescription of its preferred embodiments which follows below, when takenin conjunction with the accompanying drawings, in which like numeralsrefer to like features throughout. The following is a briefidentification of the drawing figures used in the accompanying detaileddescription.

FIG. 1 is a perspective schematic representation of a magnetic oralretractor apparatus in accordance with a first embodiment of the presentinvention, shown incorporated into the headrest of a dental chair.

FIG. 2 schematically illustrates a manner of removably mounting amagnetic oral retractor apparatus to the headrest of a dental chair, inaccordance with another embodiment of the invention.

FIG. 3 is a detail view of an external magnetic cheek gripper andintraoral magnetic retractor comprising one preferred embodiment of thepresent invention.

FIG. 4 is a sectional view of the intraoral retractor taken along lines4-4 in FIG. 3.

FIG. 5 is a similar sectional view of an alternate embodiment of theintraoral retractor depicted in FIG. 4.

FIG. 6 depicts an embodiment of the magnetic retractor apparatusaccording to an embodiment of the invention in use to expose a targetarea within a patient's oral cavity.

FIG. 7 is a plan view of another alternate embodiment of FIG. 4'sintraoral retractor, capable of illuminating a target area of a patient.

FIG. 8 is a top view of the intraoral retractor shown in FIG. 7.

FIG. 9 depicts a magnetically coupled retractor in accordance withanother embodiment of the invention.

FIG. 10 depicts a magnetic surgical retractor assembly used to securepatient tissue in place during a surgical procedure.

FIG. 11 depicts an alternate embodiment of a magnetic surgical retractorassembly used to secure patient tissue in place during a surgicalprocedure.

FIG. 12 depicts another embodiment of a magnetic surgical retractorassembly for securing patient tissue in place or distending an openingin a patient's body wall during a surgical procedure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 schematically represents a preferred embodiment of a magneticoral retractor apparatus 10 in accordance with the present invention.The retractor apparatus includes brackets 20 a and 20 b connected to theheadrest DH of an otherwise conventional dental chair. The headrest DHis connected by a conventional adjustable support DS to the dental chair(not shown in FIG. 1).

In FIGS. 1 and 2, the retractor apparatus 10 includes two mirror-imageleft- and right-hand components, the parts of which are indicated bycorresponding reference numerals with “a” and “b” suffixes. Thefollowing description omits those suffixes, it being understood thatreference to a particular feature by number indicates that thedescription applies to both the right- and left-hand components.

The retractor apparatus 10 includes an external magnetic gripper device30 with an adjustable arm 32 attached to the bracket 20 by a proximalend connector 34. The connector 34 is constructed to be removablyattachable to the bracket 20. The distal end of the arm includes amagnetic gripper element 36 that is described in more detail below inconnection with FIG. 3. The apparatus 10 further includes an upper lipholder 40 that includes an adjustable arm 42 removably attached to thebracket 20 by a proximal end connector 44. At its distal end the arm 42has a spring-loaded clamp 46, that is likewise described in more detailbelow in connection with FIG. 6. Finally, the apparatus 10 includes alower lip holder 50 that includes an adjustable arm 52 removablyattached to the bracket 20 by a proximal end connector 54. At its distalend the arm 52 has a spring-loaded clamp 56, also described in moredetail below in connection with FIG. 6.

FIG. 2 illustrates a retractor apparatus 10′ in accordance with anotherembodiment of the invention that uses a modified mounting bracket 20′.As in FIG. 1, the mounting bracket is attached to the back of a headrestDH′ connected to an otherwise conventional dental chair DC by a supportDS. The alternate mounting bracket 20′ includes a mounting plate 22 towhich the arms 32, 42 and 52 are attached as described in connectionwith FIG. 1. A cross-bar 24 is attached to the back of the headrest DH′by screws 25 or other suitable fasteners.

A thumb screw 26 passes through an opening in the cross-bar 24 andenters a slot 28 in the plate 22. A receiving nut (not shown) isslidingly mounted in the slot 28 to accept the thumb screw 26. When thethumb screw is tightened, the plate 22 is firmly secured to the crossbar 24 to fix the bracket in the desired position. With thisarrangement, the vertical position of the retractor apparatus can beadjusted in accordance with the patient's physiognomy and/or inaccordance with the particular procedure to be carried out.

It should be understood that the mounting arrangements shown in FIGS. 1and 2 are intended only as being representative of this aspect of theinvention. Without departing from the invention, the arms 32, 42 and 52can be mounted to the dental chair in any manner that accommodates theintended uses of the invention, as described herein. For example, theheadrest DH can be manufactured with built-in receptacles that removablymount the proximal ends of the arms 32 a, 32 b, 42 a, 42 b, 52 a and 52c, thus permitting the dentist or surgeon to attach to the headrest anyone or more of the gripper devices and lip holders as needed for aparticular procedure, and then to remove them if they are not needed fora different patient. These removable receptacles could be snap-fitconnectors that employ a detent mechanism to lock the arms in placewhile in use, or threaded receptacles for accepting threaded portions onthe proximal ends of the arms 32, 42 and 52. In addition, the inventionis not limited to mounting the arms to the headrest of a patient chair.They might be carried by a floor stand mounted on casters so that it canbe moved into position when a procedure requiring the apparatus is to beperformed. They could also be shortened and attached to a handle formanual use by the dentist or assistant to provide additional flexibilityin use. Those skilled in the art will be able to envision still otherarrangements that fall within the scope of the present invention.

FIG. 3 is a detail view of the magnetic gripper element 36 shown inFIG. 1. It includes a fixed portion 37 secured to the distal end of thearm 32 and a cheek gripper 38 removably secured to the fixed portion 37.The cheek gripper 38 is a permanent magnet and the fixed portion 37 is anon-magnetized magnetically permeable material. Thus, differentlyconfigured cheek grippers 38 can be used with the apparatus. Alsoillustrated in FIG. 3 is an intraoral retractor element 60, which fitswithin the patient's oral cavity. The intraoral retractor element 60 isa non-magnetized magnetically permeable material that is attracted tothe magnetic cheek gripper 38 in a manner to be described in more detailbelow in connection with FIG. 6. However, suffice it to say here thatthe patient's cheek is captured between the intraoral retractor element60 and the cheek gripper 38, and can be distended by moving the arm 32.Alternatively, or in addition, the patient's head may be oriented insuch a way as to provide the desired retraction. FIG. 4, which is across section of the intraoral retractor 60 taken along lines 4-4 inFIG. 5, shows how the retractor 60 is gently curved to match the contourof the inside of a patient's cheek, thus making the use of the retractorassembly of the present invention more comfortable than excessivedistension of the patient's lips as with conventional oral retractors.

An alternate arrangement uses a magnetized intraoral retractor and anon-magnetized cheek gripper. It is also possible for them both to bemagnetized. In that case, they can be magnetized with their magneticfields oriented such that the intraoral retractor element 60 ispositioned relative to the cheek gripper 38 in a predetermined mannerwhen in use. Suitable materials for the permanent magnet component ofthe invention are neodymium-iron-boron (NeFeB), samarium cobalt (SmCo),and alnico (AlNiCo). NeFeB and SmCo are rare-earth magnets and arebecause they provide a very strong magnetic force. SmCo is slightlypreferred because it is more resistant to corrosion than NeFeB. Alnicocan be cast or sintered and therefore can be made into different shapesmore readily. Hard ferrite or ceramic magnets, made from a combinationof either barium or strontium oxide and iron oxide can also be used. Themagnetically permeable material component of the invention can be amaterial such as cold-rolled steel or an iron-cobalt alloy (with 50%iron-50% cobalt), to name two possible materials known in the prior art.

FIG. 5 shows the intraoral retractor 60 having a corrosion-resistant,biocompatible coating 62. This coating may be a compliant material suchas silicone rubber to further increase the patient's comfort. Inaddition, the magnetic cheek gripper may also be coated with a compliantmaterial. Other variations on the construction of the intraoralretractor are also possible. For example, it can be made of a so-calledmagneto-rheological material, which is fluid-like in the absence of amagnetic field, but becomes highly viscous, approaching a solid, whenexposed to a magnetic field. The intraoral retractor could be a hollowbody of a compliant material such as silicone rubber, filled with amagento-rheological substance. Such a retractor would mold itself to thepatient's cheek before solidifying, thus providing even more comfortableretraction. Suitable materials for this purpose are sold by the LordCorporation of Cary, N.C. Still other possible constructions of theintraoral retractor include using a gauze material similar to that usednow in oral procedures, or medical grade rubber, gel/hydrogel or cloth.Gauze or cloth can be made magnetically permeable by weavingmagnetically permeable fibers into the gauze or cloth, or byinterspersing magnetically permeable, flexible or malleable stripsbetween layers of gauze or cloth. Magnetically permeable sponges mayalso be constructed in a similar fashion for use as the retractor 60. Inaddition, for thicker rolled gauze implements used in dental/oralprocedures, a magnet or magnetically permeable element can be containedwholly within the implement. Rubber or gel/hydrogel can be mademagnetically permeable by impregnation with granular or powdered formsof the materials mentioned above as being suitable for use in thepresent invention.

FIG. 6 illustrates the apparatus in use to expose a target area within apatient's oral cavity C. The patient is seated in a dental chair with aheadrest such as that shown in FIG. 1 or 2 (not seen in FIG. 6). Afterfitting the patient with a standard protective bib B, the intraoralretractor 60 is attached to the bib by a monofilament tether 64terminating in an alligator clip 66 clipped to the bib B. It ispreferable to tether the retractor in this manner to prevent the patientfrom inadvertently swallowing the retractor or choking on it if itsomehow becomes separated from the gripper 38 during the procedure. Theretractor 60 is placed within the patient's oral cavity C and the arm 32is brought into position with the gripper element 36 on the outside ofthe patient's cheek at a location opposing the oral retractor 60. Inthis manner the patient's cheek is firmly but gently captured betweenthe retractor 60 and the magnetic cheek gripper 38. The arm 32 is of aconstruction that resists movement, but can be placed in a desiredposition by exerting force thereon. In the depicted embodiment, the arm32 is segmented with adjoining segments in frictional engagement, in themanner of a supporting arm of a conventional gooseneck lamp. The arm canalso be manipulated to rotate the gripper element 36 in the direction ofthe arrow A to cause it to assume a position that will provide maximumcontact area with the patient's cheek, and thereby form a strongerconnection with the retractor 60 and minimize patient discomfort. Itwill be immediately apparent to those skilled in the art that the arm 32can be of other constructions, as long as it is sufficiently flexible tobe moved into a desired position manually, and will then maintain thatposition until moved again.

As shown in FIG. 6, the gripper device 30 is moved to a position wherethe patient's cheek is distended away from the buccal surfaces of thepatient's teeth and gums. Once the cheek is retracted, the lip holdersincluded in this embodiment of the invention can be used to hold thepatient's lips out of the way. The upper lip holder clamp 46 includes anouter member 47 hinged to an inner member 48, and the members are urgedtogether by a spring (not shown). The user squeezes the handles 49together to spread them apart and to fit them over the patient's upperlip UL as shown, and when the handles are released the spring is juststrong enough to hold the patient's lip between the members. Theadjustable arm 42 is rigid enough to hold the patient's lip in thefolded back position shown in FIG. 6. Typically, a single wire of asuitable material and thickness will suffice for this purpose. The lowerlip holder 56 is constructed generally the same manner as the upper lipholder, with like parts having corresponding “50” reference numeralscorresponding to the “40” reference numerals used to describe the upperlip holder. The lower lip holder folds back the patient's lower lip LLin the manner discussed above in connection with the upper lip holder.The clamps 46 and 56 are made of a suitable plastic material and havegently serrated edges for more securely holding the lips. The innersurfaces of the members can have a positive profile relief to preventslippage, and they can also incorporate a compliant material to be morecomfortable to the patient.

It can be seen from FIG. 6, which is based on a photograph of aprototype of the present invention in use, that the present inventionprovides a large space in the patient's oral cavity, and thereby enablesunobstructed access to the buccal surfaces of the patient's teeth andgums. The present invention takes advantage of the fact that the cheeksare more distensible than the lips, and thus retracts the cheeks, ratherthan attempting to provide space within an oral cavity by trying to pullback the patient's lips. Once the cheek is distended, it is unnecessaryto forcibly retract the lips. They only need be gently folded out of theway, thus making the retraction, which is a necessary part of theprocedure, more comfortable for the patient. This is especiallyadvantageous for lengthy procedures. In addition, there are no retractorelements traversing the patient's mouth, as with some prior artretractors, thus providing unhampered access to the target area.

FIG. 6 illustrates a procedure in which only one side of the patient'soral cavity is retracted. It is apparent from the figure that thisapplication of the invention uses only one of the “a” or “b” componentsof the retractor apparatus 10 shown in FIG. 1. In that case, the othercomponent would be moved out of the way if it were permanently attachedto the headrest DH. If the “a” and “b” components are removably attachedto the dental chair, then only those components necessary for theprocedure would be mounted to the headrest prior to preparing thepatient, and the remaining parts would be omitted. Likewise, if theapparatus were on a movable stand, or mounted in some other manner, thecomponents would be used as needed for any given procedure.

Many other variations of the parts of the invention described above arepossible. FIGS. 7 and 8 depict an alternate embodiment 60′ of theintraoral cheek retractors shown in FIGS. 4 and 5. FIG. 7 is a plan viewof the retractor 60′, showing a series of LEDs 67 on the surface of theretractor that faces the target area when the retractor is in place(FIG. 6). The LEDs are powered by a battery 68 in the retractor, as seenin the side view of FIG. 8. The battery 68 is connected to the LEDs 67through an electrical circuit (not shown) within the retractor 60′. Thecircuit includes a pressure switch 69 that activates the LEDs when theretractor is pressed against the patient's cheek by the magnetic forcebetween the cheek gripper magnet 38 and the retractor 60′.Alternatively, the line 64 connected to the retractor can be a powercord that supplies power to the LEDs. In addition, LEDs that emit lightin particular wavelength ranges may be used if the procedure involvescurable or light-activated materials, such as those used in compositebonding or cementation procedures. In another construction, the surfaceof the retractor 60 facing the patient's teeth (see FIG. 6) can bemirrored, thus affording the dentist or oral surgeon with a view of theprocedure target area.

In another alternate embodiment, the cheek gripper magnet 38 can be anelectromagnet, controllable by the dentist or oral surgeon through afoot pedal or other control (not shown). Use of an electromagnet wouldfacilitate placement of the retractor/gripper when in use. That is, itmay be desirable in some instances to use trial and error to locate theintraoral retractor 60 in the most advantageous position for particularprocedures. In that case, it will be easier to locate the intraoralretractor 60 before activating the gripper magnet 38. If thepractitioner then desires to try a different position, that can be donemore readily if the magnetic force is released.

FIG. 9 illustrates yet another application of the inventive principle ofemploying magnetic force to provide retraction of tissues forsurgical/dental procedures. The fixed portion 37 on the arm 32 can beused to hold a conventional retractor blade 70, which has a handleportion 72 and a blade 74 connected by a U-shaped contact portion 76.The handle portion is configured to fit on the fixed portion 37,replacing the magnetic cheek gripper 38 of the above-describedembodiment. In this application, the retractor blade 70 can either be amagnet (like the cheek gripper), or, more preferably, the fixed portion37 is a magnet and the retractor blade is a non-magnetized, magneticallypermeable material. Any suitable prior art retractor blade that engagesan edge of the patient's mouth can be used with this embodiment of theinvention. Suitable retractor blades are shown in U.S. Pat. No.4,971,557, U.S. Pat. No. 5,115,799, and U.S. Pat. No. 5,730,597, whichare incorporated herein by reference. This embodiment of the inventionwill be useful when it is desirable to retract the patient's lips, orperiphery of another body cavity or other tissue, to provide access tothe target area for the procedure. Like other embodiments described,this embodiment has the advantage of eliminating the need to havesomeone manually maintain the retraction force on the retractor.

FIG. 10 illustrates another aspect of the invention, for holding tissuein place during a surgical procedure. (Unless otherwise indicatedexplicitly or by context, “tissue” is meant to refer to any body tissue,including organs or other body parts.) The embodiment in FIG. 10 isparticularly adapted to holding a luminous organ, such as the colon C,out of the way during a laparoscopic procedure on nearby tissue (notshown), or for suspending it for devascularization and subsequentexcision. FIG. 10 depicts a retractor device 110 comprising threegripper devices 130 a, 130 b and 130 c for purposes of illustrating theprinciples of the present embodiment, but any number can be used inaccordance with the requirements of the particular procedure beingperformed. (As before, the remainder of this description omits the “a,”“b’ and “c” suffixes, it being understood that reference to a particularfeature by number indicates that the description applies to thecorresponding gripper device, as illustrated in FIG. 10.) Each gripperdevice 130 includes a cord 132 that has a magnetic gripper element 136at its distal end. Each gripper device also includes a cord clamp 140that tightly clamps around the cord 132 outside the body wall BW. Theretractor device 110 also includes an intraluminal retractor 160introduced into the colon C. As in the previous embodiment, the gripperelements 136 can be magnets while intraluminal retractor 160 is anon-magnetized magnetically permeable member, or both can be magnets.The materials discussed above as suitable for the gripper element 36 andthe retractor 60 can also be used for the gripper element 136 and theretractor 160.

In operation, the intraluminal retractor 160 is inserted into the colonC transanally or dropped off endoscopically, for placement in the areaof the colon that is to be retracted or excised during a laparoscopicprocedure. The gripper elements 136 are introduced through standardlaparoscopic trocars (not shown) in the body wall BW and manipulatedlaparoscopically into place on the outside surface of the colon Cadjacent the retractor 160. This captures the colon wall between thegripper elements and the retractor. A conventional small hook probe (forexample, one with a diameter of less than 3 mm) having a sharp point canthen be passed through the body wall to retrieve the cords and bringthem extracorporally so they can be introduced into the clamps 140. Theuse of hook probes of this type does not require trocars because of thesmall size of the probes. The cords 132 can then be drawn through theclamps 140, which are located to provide a suitable angle of retraction,until the colon is in the desired location, and the clamps, actingthrough the cords, hold the colon in place during the procedure. Thisembodiment, with its inherent adjustability of the cords 132 isparticularly advantageous when the tissue or organ to be manipulatedcannot reach the body wall BW. This embodiment can be used with anyluminous organ or across any tissue interface, whether it existsanatomically or is created by the surgeon specifically to manipulate thetissue in the desired fashion. The distance between the body wall andthe retracted tissue can be adjusted by changing the length of the cords132 using a laparoscopic instrument or the hook probes.

In another embodiment of the invention, the retraction arrangementdescribed above employing cords 132 and extracorporeal clamps 140 can beused without magnetic members to secure an internal organ or othertissue in a location spaced from a body wall. In that case, the gripperelements would comprise tissue clamps that lock on the tissue and aredeployed from a laparoscopic instrument or applied by hand during ahand-assisted laparoscopic (HAL) procedure. A non-magnetic applicationof this aspect of the invention may be appropriate for anatomicallocations that do s not lend themselves to the use of an intraluminalretractor (such as the retractor 160), or with tissues that cannot bemanipulated to provide a space for such a retractor. The cords may beadjusted as described above in connection with the magnetic embodimentof this aspect of the invention.

FIG. 11 illustrates another embodiment of the invention useful innon-dental surgical applications. In this embodiment, a retractor device210 includes grippers 230 a and 230 b, and corresponding intraluminalretractors 260 a and 260 b. This device also has great utility inlaparoscopic procedures, an example being the resection of a colon Calong incisions I to remove a section of the colon containing apathology such as a polyp P. In this embodiment, each gripper 230includes an arm 232 having at its distal end a gripper element 236.Meanwhile, the retractors 260 are introduced transanally into positionahead and behind the polyp P, as shown in FIG. 11. As before, thegripper elements 236 can be magnets while the intraluminal retractors260 are a non-magnetized magnetically permeable member, or all of themcan be magnets. Thus, when the gripper elements are proximate to theretractors, they interact magnetically with each other through the bodywall BW and the wall of the colon C therebetween to secure the colon inthe desired position for resection. It will be appreciated that thegripper elements and retractors can hold internal tissues in place evenif spaced apart, as long as they are sufficiently proximate to interactmagnetically and secure the tissue in place. It should also beappreciated that the retractors 260 can be held in place by a singlegripper element.

The retractors 160 and 260 can be constructed as discussed above inconnection with the dental/oral retractor device 60. For example, theretractors 160 and 260 can be comprise a hollow body of a compliantmaterial such as silicone rubber, filled with a magnetically permeablegel or a magneto-rheological substance. Nor is this aspect of theinvention limited to use in procedures involving the colon; it will beappreciated that the same operational principles apply to any luminousorgan, such as the stomach, small intestine, urinary bladder, etc. Theinvention can be used as illustrated in FIG. 11 to secure the organduring a procedure on the organ itself, but it is also capable ofsecuring the organ in place, and temporarily out of the way, duringprocedures on adjoining tissues. Further, other aspects of the inventiondescribed above with reference to the oral retractor aspect of theinvention are likewise applicable to the non-dental surgical aspects ofthe invention. This includes the use of LEDs for illumination and/orcuring, electromagnets, compliant coatings, and the magnetic andmagnetically permeable materials mentioned in connection with the oralretractor aspects of the invention.

FIG. 12 illustrates other surgical applications of the invention. Aconventional laparotomy sponge, such as the cloth-wrapped DISARP singlepatient use abdominal sponge sold by Unomedical A/S, can be modified tomake it magnetically permeable for use in the present invention. Onemodification with particular utility involves including a magnet ormagnetically permeable material within the sponge. As discussed above,this type of sponge normally will not maintain a desired positionthroughout a surgical procedure, often requiring adjustment during theprocedure. By incorporating a magnet member (a magnet or magneticallypermeable element) in the sponge, its position can be maintained throughmagnetic interaction with a cooperating magnetic member on the oppositeside of the patient's body wall. Other conventional surgical implements,such as surgical towels, can be modified to be magnetic or magneticallypermeable for use as retractors in the present invention. For example,the necessary modifications may be made in the manner discussed abovefor making gauze or cloth magnetically permeable.

The thus-modified sponge can then be used as a retractor device, asshown in FIG. 12. In one embodiment, the sponge retractor device 360 ais placed so as to pack off the tissues or an organ, such as the colonC, from the target surgical area. The sponge is held in place throughinteraction through the body wall by magnetic grippers 230 a. The spongeor other retractor element need not contact the body wall BW as shown inFIG. 12. For example, in some applications the sponge may be held inposition at a distance from the body wall by the magnetic attraction ofthe magnetic members in the sponge and grippers. Another applicationinvolves using a laparotomy sponges 360 b (or other magnetic ormagnetically permeable elements) and magnetic grippers 230 b attached toan external structure (not shown), in the place of conventionalmechanical retraction devices during a surgical procedure. By exerting aforce on the grippers 230 b, the opening OP in the body wall BW, orother tissue plane depending on the area where the invention is beingused, is distended for access to the tissue undergoing the surgicalprocedure. This will reduce the amount of trauma to the patient duringthe surgical procedure by allowing for better load distribution offorces on the tissues, hasten healing, and reduce post-operative pain.Prior mechanical retractors for body wall retraction, or retraction ofother tissue planes, typically engage the tissue at a very focal area,rather that distributing the retraction forces over a wider area.

Another aspect of the invention involves retractor devices filled withmagneto-rheological material as discussed above, for applications otherthan magnetically securing tissue across a tissue boundary as describedabove. For example, a retractor device in accordance with this aspect ofthe invention can be a hollow body of compliant material filled with amagneto-rheological substance that is fluid-like in the absence of amagnetic filed, but becomes highly viscous when exposed to a magneticfield. An example of such a retractor device is described above inconnection with FIG. 5, but it could assume any configuration suitablefor the specific tissue being retracted, including configurations usedin the prior art. A retractor device in accordance with this aspect ofthe invention is particularly adapted for retraction of delicate tissuessuch as those found in the brain, since it is pliant enough to mold tothe tissue, and then can be made sufficiently rigid to effect retractionby the application of a magnetic field, preferably by activation of anelectromagnet. The magneto-rheological material can, for example, becontained within a highly compliant vessel of silicone or otheracceptable biomaterial, perhaps with a soft coating (such as ahydrogel). The vessel would be placed like a sleeve over the blade of anotherwise conventionally configured retractor device, but which has beenmodified to be an electromagnet. The electromagnetic retractor bladewould enable the Theological sleeve to conform precisely to the tissuebefore application of the magnetic field, application of which wouldcause the fluid in the sleeve to be converted to a semi-solid asdiscussed previously. The exact mechanical properties, such as yieldstrength, of the semi-solid can be selected depending the tissuecharacteristics and needs of the surgeon. Retractor devices inaccordance with this aspect of the invention can also include otherfeatures described above, such as incorporating illumination devices.

Those skilled in the art will readily recognize that the principlesunderlying the present invention has a wide variety of applications. Inthat connection, only selected preferred embodiments of the inventionhave been depicted and described, and it will be understood that variouschanges and modifications can be made other than those specificallymentioned above without departing from the spirit and scope of theinvention, which is defined solely by the claims that follow.

1. A magnetic oral retractor assembly for distending the cheek of apatient undergoing an oral dental/surgical procedure, the apparatuscomprising: a gripper element mounted to a support structure external ofthe patient's oral cavity; an intraoral retractor device for contactingthe inner surface of the patient's cheek; wherein said gripper elementand said retractor device each include a magnetic member, at least oneof said magnetic members comprising a first magnet, and the other ofsaid magnetic members comprising a second magnet or a non-magnetizedmagnetically permeable member, said magnetic members being positioned onsaid gripper element and said retractor device for magnetically couplingsaid gripper element to said retractor device through the patient'scheek.
 2. A magnetic oral retractor assembly as in claim 1, wherein saidgripper element includes a movable mounting arm having said gripperelement at a distal end thereof, with a proximal end of said mountingarm being attached to said support structure.
 3. A magnetic oralretractor assembly as in claim 2, wherein said gripper element magneticmember is a magnet and said retractor device magnetic member is anon-magnetized magnetically permeable element.
 4. A magnetic oralretractor assembly as in claim 2, further comprising a lip holderincluding a lip clamp for grasping the patient's lip, said clamp beingmounted at a distal end of an adjustable arm with a proximal endattached to said support structure.
 5. A magnetic oral retractorassembly as in claim 4, further comprising: at least two said gripperelements, each of which is mounted on a distal end of a separatemounting arm, said mounting arms having their proximal ends adapted tobe removably attached to said support structure for use with oppositesides of the patient's oral cavity; and at least four said lip holders,each of which is mounted at the distal end of a separate said adjustablearm with said proximal end thereof adapted to be removably attached tosaid support structure, wherein pairs of said lip holders are disposedfor use with an associated said gripper element to hold the upper andlower lips on opposite sides of the patient's oral cavity.
 6. A magneticoral retractor assembly as in claim 5, wherein said support structureincludes a headrest of a dental chair.
 7. A magnetic oral retractorassembly as in claim 6, wherein said support structure includes abracket with connectors for removably mounting said proximal ends ofsaid mounting arms and said adjustable arms.
 8. A magnetic oralretractor assembly as in claim 7, wherein said bracket comprises aleft-hand component for mounting at least one said mounting arm and twosaid adjustable arms and a right-hand component for mounting at leastone said mounting arm and two said adjustable arms.
 9. A magnetic oralretractor assembly as in claim 7, wherein said bracket is removablymounted to said headrest.
 10. A magnetic oral retractor assembly as inclaim 1, wherein said gripper element magnetic member is anelectromagnet.
 11. A magnetic oral retractor assembly as in claim 1,wherein said intraoral retractor device comprises at least one of amagnetically permeable material coated with a compliant biocompatiblematerial and a compliant hollow member having magneto-rheologicalmaterial therein.
 12. A magnetic oral retractor assembly as in claim 1,wherein said intraoral retractor device includes lighting elements forilluminating an area within the patient's oral cavity.
 13. A magneticsurgical retractor assembly for securing a tissue of a patientundergoing a medical procedure, the assembly comprising: a gripperelement; and a retractor device for engaging a portion of the tissue;wherein said gripper element and said retractor device each include amagnetic member, at least one of said magnetic members comprising afirst magnet, and the other of said magnetic members comprising a secondmagnet or a non-magnetized magnetically permeable member, said magneticmembers being positioned on said gripper element and said retractordevice for magnetically coupling said gripper element to said retractordevice to enable said gripper element to exert a force on said retractordevice to manipulate the tissue.
 14. A magnetic surgical retractorassembly as in claim 13, wherein said retractor device is adapted forplacement within a lumen of a hollow organ or a space within a tissue sothat said gripper element interacts magnetically with said retractordevice through a wall of the organ or a tissue interface.
 15. A magneticsurgical retractor assembly as in claim 14, wherein only one of saidmagnetic members is a magnet.
 16. A magnetic surgical retractor as inclaim 13, wherein said gripper element and said retractor device areadapted to interact magnetically with each other across a tissueboundary within the body cavity.
 17. A magnetic surgical retractordevice as in claim 13, wherein said gripper element includes structurefor extending through a body wall of the patient for securing the organor tissue within the body cavity at a location spaced from the bodywall.
 18. A magnetic surgical retractor assembly as in claim 13, whereinsaid gripper element magnetic member and said retractor device areadapted to interact magnetically through a body wall of the patient. 19.A magnetic surgical retractor assembly as in claim 13, wherein saidretractor device comprises at least one of a magnetically permeablematerial coated with a compliant biocompatible material and a complianthollow member having magneto-rheological material therein.
 20. Amagnetic surgical retractor assembly as in claim 13, wherein saidretractor device is a compliant surgical implement.
 21. A magneticsurgical retractor assembly as in claim 20, wherein said compliantsurgical implement includes at least one of a magnet and magneticallypermeable material.
 22. A magnetic surgical retractor assembly as inclaim 13, wherein said retractor device includes lighting elements forilluminating an area of the patient.